ARAMIS (The American Rheumatism Association Medical Information System) is a rheumatic disease computer data bank system containing prospective longitudinal clinical data for over 23,000 patients, 160,000 patient encounters, and 150,000 patient- years of observation. The system operates from an IBM 370/3084A computer at Stanford University accessible nationally through TYMNET or TELENET communication networks, and is represented additionally as a distributed system with data banks resident on personal computers with augmented disk storage. The program has two major aims: first, to continue to develop a national data resource of high quality, longitudinal, accessible clinical data, and second, to employ these data in a systematic multi-center investigate program addressing major clinical questions in the rheumatic diseases. The program is based upon the premises that chronic diseases have become our most prevalent national health problem, that their study requires observation over prolonged time periods, that patient outcome results from a complex interplay of multiple factors, and that these questions need observational, in addition to experimental, study. Forty clinical investigators and epidemiologists at 12 institutions undertake over 50 projects annually. The present proposal includes long-term outcome studies of rheumatoid arthritis, radiologic progression, of mortality from rheumatic illness, outcome after total joint replacements, and of long-term outcomes of systemic lupus, scleroderma, eosinophilic fasciitis, fibrositis, and others. Studies in Sun City, with University of Pennsylvania graduates, and with the HANES I follow-up program seek to identify risk factors for osteoarthritis and aging. Analyses of socioeconomic factors, psychological factors, and compliance in rheumatoid arthritis, and the impact of new (and contemplated) changes in reimbursement upon care are examined. Long-term toxities of methotrexate, total lymphoid irradiation, and anti-inflammatory drugs upon gastrointestinal system pathology are analyzed. With this project 18 years of data development at numerous institutions are brought to bear upon major clinical questions, and large, detailed, and high quality longitudinal patient datasets are made nationally available.